The present invention relates to pulse rate monitors, and more particularly, to a superficial temporal artery (STA) monitor that can be miniturized.
One type of prior art STA monitor uses a microwave Doppler radar system to detect motion of the artery. The system comprises an oscillator, a directional coupler, a circulator, a mixer, and an I.F. amplifer. Since all of these components, except for the I.F. amplifier, operate at microwave frequencies, they must be placed close together to avoid attenuation, spurious signal pick up, noise, and phase changes caused by any interconnecting cable, and any motion thereof, conveying microwave signals. Thus all of the components, except for the I.F. amplifier, must be disposed near the subject to ensure sufficient coupling thereto to obtain a reliable pulse rate signal. The result is a bulky monitor that cannot be easily placed in a restricted volume, e.g., a helmet.
It is, therefore, desirable to provide a miniturized pulse rate monitor.